Cindy Qiu from KGO Television's program "7Live," witnessed the incident. The station is the San Francisco-based sister station of OnTheRedCarpet.com's parent company, KABC Television.

She said Armstrong was approached by a flight attendant, who told him to pull his pants up. She said the rocker initially dismissed the request and asked: "Don't you have better things to do then worry about that?"

When the flight attendant repeated the request and threatened to have the rock star removed from the plane, Armstrong reportedly replied: "I'm just trying to get to my (expletive) seat."

Armstrong and his travel partner were then removed from the flight, Qiu said.

Southwest Airlines issued a statement to the Associated Press, claiming that Armstrong's complaint has since been resolved.

"As soon as we became aware of what had happened, we reached out to apologize for this customer's experience," Southwest spokesman Brad Hawkins said in a statement. "He elected to take the next flight. We followed up with this customer and involved employees to get more details and, in our latest conversations, understand from the customer the situation was resolved to his satisfaction."

Southwest Airlines has been in hot water with celebrities before, having famously booted "Mallrats" director Kevin Smith from an Oakland to Burbank flight because of his weight, saying he didn't fit properly into a single seat. Smith blasted the airline on Twitter and in a podcast for the incident.

In June, a University of New Mexico football player was kicked off a U.S. Airways flight over his saggy pants and is subsequently suing the airline.